JPH05130321A - Hand scanner device - Google Patents

Abstract

PURPOSE:To always obtain image data excellent in reproducibility by changing the lighting time of an original illuminating light source in response to the moving speed of a reading sensor part and also changing the reading speed of a reading sensor. CONSTITUTION:When the velocity signal VST inputted from a velocity signal generating part 122 exceeds the upper limit of a prescribed speed range, a control part 2 controls a pulse control part 3 to increase the reading speed of a reading sensor part 111. At the same time, the part 2 controls am LED array control part 4 to prolong the lighting time of an LED array 113. When the signal VST is set at the speed lower than the lower limit level of a prescribed speed range, the lighting time of the array 113 is shortened with the control of the part 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hand scanner device for converting the contents of an original into image data by manually moving the original in the sub-scanning direction.

[0002]

2. Description of the Related Art Conventionally, this type of hand scanner has a structure as shown in FIG. 31 is a rotatable rotary shaft, 32 is a moving roller provided on the rotary shaft 31,
The diameter takes the linear density in the sub-scanning direction into consideration. For example, the diameter of the roller 32 is set so that the roller 32 coincides with the next reading line of the original 100 when the roller 32 rotates by an angle. Also, moving rollers 3
The lower end of 2 projects slightly toward the document side from the reading unit 11, and can be smoothly moved on the document 100 only by the moving roller 32. Reference numeral 33 is an encoder unit, which is an encoder plate 34 having slits on the outer circumference of the disk.
And a detector 35 for detecting the slit and an encoder plate 34 for rotating in synchronization with the moving roller 32.
The belt 36 and the belt 37 are provided. The encoder plate 34 is provided with a plurality of slits at equal intervals on the circumference corresponding to one line scanning period. Therefore, when the reading unit 11 moves, a pulse signal corresponding to the speed is generated from the detector 35, and this pulse is input to the line start detecting unit 123 shown in FIG.

FIG. 7 is a diagram showing a control system of the hand scanner. When the pulse signal corresponding to the speed of the hand scanner is input from the detector 35 to the line start detection unit 123, the line start detection unit 123 outputs the line start pulse LST for each rotation angle of the roller 32 corresponding to one line scanning period. It is generated and output to the control unit 2. When the line start pulse LST is input, the control unit 2 turns on the LED array 113 for a predetermined time via the sensor drive unit 112 and drives the reading sensor unit 111 to photoelectrically convert the content of the original 100. Read sensor unit 11
The image signal obtained from 1 is input to the image signal processing unit 5 and subjected to processing such as binarization.

The above-mentioned hand scanner device is used as the original document 10.
By manually scanning (moving) in the direction of the arrow shown in FIG. 6 along 0, the characters, figures, etc. on the document 100 can be read as image data. here,
When the moving speed of the hand scanner device is unstable, for example, when the moving speed exceeds the upper limit of the speed in the predetermined range and is too high, the sensor driving unit 112 is used although the moving speed of the reading sensor 111 is high. Read sensor 11 output from
Since the shift pulse period of 1 is constant, the reading sensor 1
Since 11 reaches the reading position of the next line before reading one line, there arises a problem that information of all one line cannot be read. Moreover, since the LED array 113 in the reading unit 11 irradiates the original 100 only for a period less than a predetermined time, the level of the image signal becomes low as a whole.

On the other hand, contrary to the above, when the moving speed of the hand scanner is less than or equal to the lower limit of the predetermined speed range, the reading unit 11
Since the internal light source irradiates the document 100 for a predetermined time or longer, there arises a problem that the level of image data to be read becomes high overall. Such instability of the moving speed of the hand scanner device may cause density unevenness in the obtained image data, or may appear as a discontinuity in the image, so that the content of the original document to be read can be faithfully reproduced. The drawback is that you cannot do it. Conventionally, in order to avoid such drawbacks, the speed at which the hand scanner is moved is limited within a predetermined range.
If such a limitation is provided, the operability of the hand scanner is deteriorated, and the operator is burdened when reading the document.

[0006]

As described above, when the moving speed of the hand scanner is unstable, density unevenness occurs in the read image data or image discontinuity occurs, and the content of the document to be read is changed. It had the drawback that it could not be faithfully reproduced.

Therefore, the present invention eliminates the above-mentioned drawbacks by changing the lighting time of the light source for irradiating the original according to the moving speed of the reading sensor portion and changing the reading speed of the reading sensor. It is an object of the present invention to provide a hand scanner device that can always obtain image data with good reproducibility.

[0008]

According to the present invention, a reading sensor for obtaining image data by manually moving in the sub-scanning direction on a document illuminated by an illuminating device, and a moving speed of the reading sensor in the sub-scanning direction are described. In a hand scanner device including speed detecting means for detecting, a judging means for judging whether or not the speed of the reading sensor section detected by the speed detecting means exceeds an upper limit or a lower limit of a predetermined speed range, and this judging means When it is determined that the speed of the reading sensor unit exceeds the upper limit or the lower limit of the predetermined speed range, the irradiation amount for changing the original document irradiation amount within the one-line reading period by the illumination unit as compared with the case where it is in the predetermined speed range. When the speed of the reading sensor unit exceeds the upper limit of the predetermined speed range by the control unit and the judging unit, the reading speed of the reading sensor unit Having the configuration and a faster control means.

[0009]

In the hand scanner device of the present invention, the judging means judges whether the speed of the reading sensor section detected by the speed detecting means exceeds the upper limit or the lower limit of the predetermined speed range. When the determination unit determines that the speed of the reading sensor unit exceeds the upper limit or the lower limit of the predetermined speed range, the irradiation amount control unit sets the document irradiation amount within the one-line reading period by the illumination unit within the predetermined speed range. Change it compared to the case. The control unit increases the reading speed of the reading sensor unit when the judgment unit judges that the speed of the reading sensor unit exceeds the upper limit of the predetermined speed range.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a hand scanner device of the present invention. Reference numeral 1 is a hand scanner having a reading unit 11 and a speed detection device 12. 2 is a reading unit 1
1, a control unit 3 for controlling the driving of the rotary shaft 31 and the like, a pulse control unit 3 for generating a shift pulse for driving the reading sensor unit 111 and controlling the cycle of the pulse, 4
Is an LED array control unit that controls the lighting time of the LED array 113, and 5 is an image signal processing unit that processes the image signal input from the reading unit 11. The reading unit 11 includes a reading sensor unit 111 that converts an image into image data, and a sensor driving unit 112 that drives the reading sensor unit 111. The speed detection device 12 includes a speed sensor unit 121 for converting the speed of the hand scanner into an electric signal, and the speed sensor unit 121.
It comprises a speed signal generator 122 for converting the electric signal from V.sub.ST to a speed signal VST and a line start detector 123 for generating a line start pulse LST based on the electric signal input from the speed sensor unit 121. still,
The reading sensor unit 111 is provided with an LED array 113, which irradiates a document (not shown).

Next, the operation of this embodiment will be described. When the hand scanner 1 is placed on a document (not shown) and the operator moves it, the moving roller 32 and its rotating shaft 3 are moved.
1 rotates. Along with this, the encoder plate 34 also rotates in synchronization with the rotation of the rotary shaft 31. The detector 35 detects passage of a slit provided in the rotating encoder plate 34 and converts it into an electric signal. This electric signal is input to the speed detection unit 122 and the line start detection unit 123. The line start detection unit 123 decodes the input signal, generates a line start pulse LST for each rotation angle of the moving roller 32 corresponding to one line scanning time, and outputs this to the control unit 2. .. The speed detection unit 122 monitors the input interval of the input signal, generates the speed signal VST, and outputs it to the control unit 2. When the line start pulse LST is input from the line start detection unit 123, the control unit 2 instructs the reading sensor 111 to start reading a document via the pulse control unit 3 and the sensor driving unit 112. At this time, the pulse control unit 3 generates a shift clock SCK and supplies this clock to the reading sensor unit 111 via the sensor driving unit 112. As a result, the reading sensor 111 turns on the LED array 113,
The reflected light from a document (not shown) is photoelectrically converted to start accumulating charges. The hand scanner 1 moves one line,
When the next line start pulse LST is input from the line start detector 123, the controller 2 causes the pulse controller 3 to operate.
Also, the accumulated charge in front of the reading sensor 111 is output to the image signal processing unit 5 as image data via the sensor driving unit 112.

By the way, since the operator of the hand scanner 1 is manually moved in the sub-scanning direction, the moving speed is not constant. Therefore, hereinafter, (1) the hand scanner is moving within the set speed range, (2) is moving at a speed less than the lower limit of the setting range, and (3) is within the setting range. The operation of the hand scanner device in three speed states when moving at a speed exceeding the upper limit of 1 will be described.

First, the operation when the hand scanner is moving at a speed within the set range of (1) (steady state) will be described. FIG. 2 is a time chart showing the timing of on / off control of the LED array 113 when the hand scanner 1 is in a steady state. FIG. 2A shows the speed signal VST output from the speed signal generator 122 based on the pulse detected by the detector 35 in the slit of the encoder plate 34 shown in FIG. Then, the cycle becomes t _SPM . FIG. 2B shows a line start pulse LST generated every time the line start detecting unit 123 counts a fixed number of the speed signal VST. Since the interval t _LSPM of this line start pulse LST is synchronized with the interval at which the moving roller 32 moves by one line,
It is generated every time the hand scanner 1 shown in FIG. 1 is moved by one line. FIG. 2C shows an LED array control signal LE for turning on / off the LED array 113 in the reading unit 11.
DC is shown, and the LED array control unit 4 outputs the control signal to the sensor drive unit 112 to turn on and off the LED array 113. In this example, when the line start pulse LST is input to the control unit 2, the LED array control signal LEDC is set to the low level for t _LEDM time, and the LED array 113 is turned on for the storage time required by the reading unit 11, _{And the} time t _LEDM
After that, the LED array control signal LEDC is set to a high level to turn off the LED array 113. On the other hand, FIG. 2D shows the shift pulse SC output from the pulse control unit 3 to the reading sensor unit 111 via the sensor driving unit 112.
K is shown, and in the steady state, the cycle is set to t _SCM .

Since the hand scanner 1 is moving in the steady state in each of the signals shown in FIG. 2, the line start pulse LST is periodically generated every t _LSPM as shown in FIG. , The speed signal VST is t as shown in FIG.
It is generated periodically for each _SPM . On the other hand, the LED array control signal LEDC _becomes low level for t _LEDM as shown in FIG. 2C starting from the generation of the line start pulse LST, and the LED array 113 is lit up during this period.
When the time t _LEDM has passed, the LED array 113 is turned off until the next line _{start pulse} LST is generated. The time when the LED array control signal LEDC is at the low level is the charge accumulation time of the reading sensor unit 111. Further, in this case, since the hand scanner 1 is moving at a speed within a predetermined range in a steady state, the shift clock SCK shown in FIG. 2D is generated from the pulse control unit 3 at the cycle t _SCM , and It is supplied to the reading sensor unit 111 via the sensor driving unit 112, and this reading sensor unit 111
To operate.

FIG. 3 shows (2) the time chart of each signal when the hand scanner 1 moves in a state of being less than the lower limit value of the speed in the predetermined range. In this case,
As shown in (A), the generation interval of the speed signal VST becomes t _SPL , which is longer than that shown in FIG. 2 (A). Accordingly, as shown in FIG. 3 (B), the line start pulse LST is generated. Also _becomes t _LSPL , which is longer than that shown in FIG. Therefore, t _SPL > t _SPM and t _LSPL
> T _LSPM . However, FIG. 3 (C)
As shown in FIG. 6, the LED array control signal LEDC is _{kept low for} a period of t _LEDL from the time of generation of the line start pulse LST.
The LED array 113 is turned on and the LED array 113 is turned on during this period. Moreover, the pulse control unit 3 sets the interval at which the LED array signal LEDC is at a low level to a time shorter than that in the steady state so that the relationship of t _LEDL <t _LEDM occurs. However, also in this case, as shown in FIG.
The cycle of the shift clock SCK remains t _SCM and is the same as that in the steady state. However, since the lighting time of the LED array 113 is short as described above, the irradiation amount on the document should not be too large. Has been adjusted. Here, since the image signal level output from the reading sensor unit 111 is proportional to the accumulation time, that is, the irradiation time of the LED array 113 onto the document, the moving speed of the hand scanner is less than the lower limit of the predetermined speed range as in this example. In such a case, since the LED array 113 lights up and irradiates the original for a shorter time than the steady state shown in FIG. 2, the accumulation time is almost the same as the steady state. Therefore, the accumulation time does not become too long.

FIG. 4 shows the time charts of the above signals when the hand scanner of (3) moves at a speed higher than the upper limit of the predetermined speed range. In this case,
As shown in (A), the cycle of the speed signal VST becomes t _SPS , which is shorter than that in the steady state. Therefore, as shown in FIG. 4B, the generation interval of the line start pulse LST is also t _LSPS, which is shorter than that in the steady state shown in FIG. 2B. Therefore, t _SPS <t
_It becomes _SPM and t _LSPS <t _LSPM . However, at this time, as shown in FIG. 4C, the low level period of the LED control signal LEDC becomes t _LEDC , which is longer than that in the steady state shown in FIG. _2D . Therefore, t _LEDC > t _LEDM . As a result, the lighting time of the LED array 113 is lengthened and a reduction in the irradiation amount of the document due to the increased moving speed of the reading unit 11 is prevented.
The charge accumulation time of 1 is almost the same as that in the steady state,
It is possible to eliminate a decrease in the level of the obtained image data. Moreover, at this time, the pulse control unit 3 changes the cycle of the shift clock SCK according to an instruction from the control unit 2 as shown in FIG.
As shown in FIG. 2, t _SCS is set to be shorter than that in the steady state shown in FIG. 2D to accelerate the reading speed of the image data of the reading sensor unit 112 and increase the moving speed of the reading unit 11. , So that the original can be converted into image data.

FIG. 5 is a flow chart showing the reading operation of the control unit 2 shown in FIG. In step 501, the reading unit 11 starts reading, the generation interval of the line start pulse LST is set to t _LSPM , and the LED control signal LED
After the generation interval of C is set to t _LEDM and the cycle of the shift clock is set to t _SCM , the input of the line start pulse LST is _awaited in step 502. Line start pulse L
When ST is input, the control unit 3 proceeds to step 503 and sets the LED control signal LEDC to the low level for the set time, and the LED array 113 of the reading sensor unit 111.
After turning on, the process proceeds to step 504. Step 504
Then, it is determined from the speed signal VST whether the moving speed of the reading unit 11 exceeds the upper limit value.
If not, go to step 506. In step 505, the control unit 2 sets the generation interval of the line start pulse LST to t _LSPS , sets the low level period of the LED control signal LEDC to t _LEDS , sets the cycle of the shift clock SCK to t _SCS , and proceeds to step 506. Step 5
At 06, it is determined whether or not the speed of the reading unit 11 is less than the lower limit, and if so, the process proceeds to step 507, and if not, the process proceeds to step 508. In step 507, the control unit 3 sets the generation interval of the line start pulse LST to t.
_LSPL , the low level period of the LED control signal LEDC is set to t _LEDL, and the cycle of the shift clock SCK is set to t _SCM, and then the _routine proceeds to step 508. In step 508, it is determined whether or not the speed of the reading unit 11 is in a steady state within a predetermined range. If yes, the process proceeds to step 509, and if not, the process proceeds to step 510. Step 509
Then, the control unit 3 sets the generation interval of the line start pulse LST to t _LSPM , sets the low level period of the LED control signal LEDC to t _LEDM, and _sets the cycle of the shift clock SCK to t _SCM.
After that, the process proceeds to step 510. L in step 510
It is determined whether the lighting time of the ED array 113 has passed,
If it has not passed, the process returns to step 503, and if it has passed, the process proceeds to step 511. After turning off the LED array 113 in step 511, the process proceeds to step 512. In step 512, it is determined whether or not the reading is completed. If it is not completed, the process returns to step 502, and if it is completed, the process is completed.

According to the present embodiment, when the moving speed of the hand scanner 1 is lower than the lower limit of the predetermined speed range, the LED array 113 is started from the time when the line start pulse LST is generated.
By turning on the light for a shorter time than the steady state, it is possible to prevent the charge accumulation time of the reading sensor unit 111 from being too long and the image signal level becomes high. It is possible not to impair the reproducibility of. Also, the hand scanner 1
When the moving speed of the LED increases and exceeds the upper limit of the speed in the predetermined range, the LED starts from the time when the line start pulse LST is generated.
By turning on the array 113 for a longer time than the steady state, it is possible to prevent the charge accumulation time of the reading unit 11 from being too short and the image signal level to be low.
It is possible to always maintain an appropriate image signal level so as not to impair image reproducibility. Moreover, when the moving speed of the hand scanner 1 exceeds the upper limit, the cycle of the shift clock SCK supplied to the reading sensor unit 111 is made shorter than that in the steady state to increase the image reading speed. Even if the moving speed exceeds the upper limit, the original can be read, and the interruption of the image can be prevented.

[0019]

As described above, according to the hand scanner device of the present invention, the lighting time of the light source for illuminating the original is changed according to the moving speed of the reading sensor portion, and the reading speed of the reading sensor is changed. As a result, it is possible to always obtain image data with good reproducibility.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a hand scanner device of the present invention.

2 is a time chart of each signal for explaining the operation when the moving speed of the hand scanner of the apparatus shown in FIG. 1 is in a steady state.

3 is a time chart of each signal for explaining the operation when the moving speed of the hand scanner of the apparatus shown in FIG. 1 is less than a predetermined range.

4 is a time chart of each signal for explaining the operation when the moving speed of the hand scanner of the apparatus shown in FIG. 1 exceeds the upper limit of a predetermined range.

5 is a flowchart showing an example of image reading control of a control unit shown in FIG.

FIG. 6 is a diagram showing an example of a hand scanner of a conventional hand scanner device.

FIG. 7 is a diagram showing an example of a control system of a conventional hand scanner device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hand scanner 2 ... Control part 3 ... Pulse control part 4 ... LED array control part 5 ... Image signal processing part 11 ... Reading part 31 ... Rotating shaft 32 ... Roller 34 ... Encoding plate 35 ... Detector 111 ... Reading sensor part 112 ... Sensor driver 113 ... LED array 122 ... Speed signal generator 123 ... Line start detector

Claims (1)

[Claims] 1. A reading sensor for obtaining image data by manually moving in a sub-scanning direction on a document illuminated by an illuminating means, and a speed detecting means for detecting a moving speed of the reading sensor in the sub-scanning direction. In the provided hand scanner device, a determining unit that determines whether the speed of the reading sensor unit detected by the speed detecting unit exceeds an upper limit or a lower limit of a predetermined speed range, and the speed of the reading sensor unit is determined by the determining unit. When it is determined that the upper limit or the lower limit of the predetermined speed range is exceeded, the irradiation amount control means for changing the document irradiation amount within the one-line reading period by the illumination means as compared with the case where it is in the predetermined speed range, and the determination means. When it is determined that the speed of the reading sensor unit exceeds the upper limit of the predetermined speed range, the control means for increasing the reading speed of the reading sensor unit. A hand scanner device characterized by being provided.